Semiconductor light emitting device and method of fabricating the same

ABSTRACT

Provided is a semiconductor light emitting device and a method of fabricating the same. The semiconductor light emitting device comprises: a first conductive semiconductor layer; an active layer on the first conductive semiconductor layer; a second conductive semiconductor layer on the active layer; a second electrode part on the second conductive semiconductor layer; an insulation layer on the second electrode part; and a first electrode part on the insulation layer, a portion of the first electrode part being electrically connected to the first conductive semiconductor layer.

TECHNICAL FIELD

Embodiments relate to a semiconductor light emitting device and a methodof fabricating the same.

BACKGROUND ART

Group III-V nitride semiconductors have been variously applied tooptical devices such as blue and green light emitting diodes (LEDs),high speed switching devices such as a Metal Semiconductor Field EffectTransistor (MOSFET) and a Hetero junction Field Effect Transistor(HEMT), and light sources of lighting devices or display devices.Especially, a light emitting device using a group III nitridesemiconductor has a direct transition-type band gap corresponding to theranges from a visible ray to an ultraviolet ray to realize highefficient light emission.

The nitride semiconductor is mostly applied to LEDs or laser diodes(LDs). Research for improving a manufacturing process or lightefficiency has been continuously made.

DISCLOSURE OF INVENTION Technical Problem

Embodiments provide a semiconductor light emitting device comprising afirst electrode part connected to a first conductive semiconductor layerin a via form, on a light emitting structure, and a method offabricating the same.

Embodiments provide a semiconductor light emitting device where a secondelectrode part spatially overlaps a partial pattern of a first electrodepart, on a light emitting structure, and a method of fabricating thesame.

Embodiments provide a semiconductor light emitting device capable ofimproving the degree of pattern freedom for first and second electrodeparts, and a method of fabricating the same.

Technical Solution

An embodiment provides semiconductor light emitting device comprising: afirst conductive semiconductor layer; an active layer on the firstconductive semiconductor layer; a second conductive semiconductor layeron the active layer; a second electrode part on the second conductivesemiconductor layer; an insulation layer on the second electrode part;and a first electrode part on the insulation layer, a portion of thefirst electrode part being electrically connected to the firstconductive semiconductor layer.

An embodiment provides a semiconductor light emitting device comprising:a first conductive semiconductor layer; an active layer on the firstconductive semiconductor layer; a second conductive semiconductor layeron the active layer; a second electrode part on the second conductivesemiconductor layer; an insulation layer on the second electrode part;and a first electrode part on the insulation layer, a portion of thefirst electrode part being electrically connected to the firstconductive semiconductor layer in a via form.

An embodiment provides a method of fabricating a semiconductor lightemitting device comprising: forming a first conductive semiconductorlayer, an active layer, and a second conductive semiconductor layer;forming at least one via hole in the second conductive semiconductorlayer, the via hole penetrating a portion of the first conductivesemiconductor layer; forming a second electrode part on the secondconductive semiconductor layer around the via hole; forming aninsulation layer on the second electrode part and the via hole; andforming a first electrode part on the insulation layer, a portion of thefirst electrode part being electrically connected to the firstconductive semiconductor layer through the via hole.

Advantageous Effects

Embodiments provide the degree of pattern freedom for first and secondelectrode parts disposed on and under an insulation layer.

Embodiments split patterns of electrodes on and under an insulationlayer to supply a diffused current.

Embodiments improve external light emitting efficiency.

Embodiments arrange a partial pattern of an electrode part to spatiallyoverlap so as to improve a light emitting area.

Embodiments provide a high output LED.

Embodiments improve the degree of pattern freedom for an electrode part.

Embodiments improve tolerance for ESD.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side-sectional view illustrating a semiconductor lightemitting device according to an embodiment.

FIG. 2 is a side-sectional view taken along a line A-A of FIG. 1.

FIG. 3 is a side-sectional view taken along a line B-B of FIG. 1.

FIG. 4 is a plan view of FIG. 1 and illustrates an example of currentdistribution in an electrode part.

FIGS. 5 to 16 are views illustrating a process of fabricating asemiconductor light emitting device according to a first embodiment.

FIGS. 17 to 20 are views illustrating a process of fabricating asemiconductor light emitting device according to a second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a semiconductor light emitting device and a method offabricating the same according to embodiments will be described indetail with reference to the α-companying drawings. In the followingdescription, when a layer (or film) is referred to as being on and underanother layer, its description will be made with reference to theaccompanying drawings. The thickness of each layer may be described asone example, and is not limited to the thicknesses of the accompanyingdrawings.

In the description of embodiments, it will be understood that when eachlayer (or film), area, pattern, or structure is referred to as being“on/under” another substrate, layer (or film), area, pad, or pattern, itcan be “directly” on the another substrate, layer (or film), area, pad,or pattern, or intervening layers may also be “indirectly” present.

FIG. 1 is a side-sectional view illustrating a semiconductor lightemitting device according to a first embodiment. FIG. 2 is aside-sectional view taken along a line A-A of FIG. 1. FIG. 3 is aside-sectional view taken along a line B-B of FIG. 1.

Referring to FIG. 1, a semiconductor light emitting device 100 comprisesa substrate 110, a light emitting structure 115, a transparent electrodelayer 145, an insulation layer 150, a first electrode part 160, and asecond electrode part 170.

The substrate 110 may be formed of one selected from the groupcomprising Al₂0₃, GaN, SiC, ZnO, Si, GaP, InP, and GaAs. A convex andconcave pattern may be formed on the substrate 110 and has a lens form.

The light emitting structure 115 is formed on the substrate 110. Here,another semiconductor layer, for example, a buffer layer (not shown)or/and an undoped semiconductor layer (not shown), may be formed betweenthe substrate 110 and the light emitting structure 115. The buffer layerand the undoped semiconductor layer are disposed to reduce a latticeconstant difference between the substrate 110 and the semiconductor orto prevent defectiveness, and this is not limited to the buffer layerand the undoped semiconductor layer.

The light emitting structure 115 comprises a first conductivesemiconductor layer 120, an active layer 130, and a second conductivesemiconductor layer 140. Here, the light emitting structure 115 mayfurther comprise another semiconductor layer on or under each layer andis not limited to the layer structure.

The first conductive semiconductor layer 120 is formed on the substrate110. The first conductive semiconductor layer 120 may be realized with asemiconductor having an empirical formula of In_(x)Al_(y)Ga_(1-x-y)N(0≦x≦1, 0≦y≦1, 0≦x+y≦1) and is doped with a first conductive dopant. Thefirst conductive semiconductor layer 120 is a compound semiconductor ofa group III element and a group V element and may be formed of GaN, InN,AlN, InGaN, AlGaN, InAlGaN, or AlInN. When the first conductivesemiconductor layer 120 is an N-type semiconductor layer, the firstconductive dopant is an N-type dopant and the N-type dopant comprisesSi, Ge, or Sn.

The active layer 130 is formed on the first conductive semiconductorlayer 120. The active layer 130 may have a single quantum well structureor a multi quantum well structure. The active layer 130 has a period ofa well layer and a barrier layer through a compound semiconductormaterial of a group III element and a group V element. For example theperiod may comprise a period of an InGaN well layer/a GaN barrier layeror a period of an AlGaN well layer/a GaN barrier layer.

The active layer 130 is formed of a material having band gap energybased on a wavelength of an emitted light. For example, if thewavelength is a blue light of 460 nm to 470 nm, the active layer 130 mayhave a single or multi quantum well structure by a period of an InGaNwell layer/a GaN barrier layer. The active layer 130 may comprise amaterial for emitting colored light such as blue wavelength light, redwavelength light, and a green wavelength light.

A conductive clad layer (not shown) may be formed on or/and under theactive layer 130, and the conductive clad layer may be realized with anAlGaN layer.

A second conductive semiconductor layer 140 is formed on the activelayer 130. The second conductive semiconductor layer 140 may be realizedwith a semiconductor having an empirical formula ofIn_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1) and is doped with asecond conductive dopant. The second conductive semiconductor layer 140may be formed of a compound semiconductor of a group III element and agroup V element such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.When the second conductive semiconductor layer 140 is a P-typesemiconductor layer, the second conductive dopant is a P-type dopant,and the P-type dopant comprises Mg, Zn, Ca, Sr, or Ba.

Additionally, a third conductive semiconductor layer (not shown) isformed on the second conductive semiconductor layer 140. The thirdconductive semiconductor layer may be formed of an N-type semiconductorlayer if the second conductive semiconductor layer 140 is formed of aP-type semiconductor layer, and the third conductive semiconductor layermay be formed of a P-type semiconductor layer if the second conductivesemiconductor layer 140 is formed of an N-type semiconductor layer.

The light emitting structure 115 may be formed of a P-N junction, an N-Pjunction, a P-N-P junction, or an N-P-N junction within the technicalscope of embodiments. Each layer may be formed of a single layer or amulti layer, and another semiconductor layer may be added on or undereach layer. Each layer is not limited to a stacked layer structure ofthe components.

The transparent electrode layer 145 is formed on the second conductivesemiconductor layer 140 of the light emitting structure 115. Thetransparent layer 145 may be formed of at least one of materials forlight transmittivity and ohmic-contact such as indium tin oxide (ITO),indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminumzinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium tinoxide (IGTO), aluminium zinc oxide (AZO), antimony tin oxide (ATO), ZnO,RuOx, TiOx, IrOx, SnO₂, and NiAu, but is not limited thereto. Thetransparent electrode layer 145 distributes current and supplies it tothe active layer 130. The transparent electrode layer 145 may not beformed on the second conductive semiconductor layer 140.

The second electrode part 170 and 175 may be formed on the transparentelectrode layer 145 and is divided into a second electrode 170 and asecond electrode pad 175. The second electrode 170 and the secondelectrode pad 175 may be directly or/and indirectly connected to atleast one of the transparent electrode layer 145 and the secondconductive semiconductor layer 140. The second electrode pad 175 may beelectrically connected to the second conductive semiconductor layer 140through hole of the transparent electrode layer 145.

Additionally, the second electrode part 170 and 175 may be directlyformed on the second conductive semiconductor layer 140 if thetransparent electrode layer 145 is not formed. Another material layer(e.g., a reflective electrode layer) other than the transparentelectrode layer 145 may be formed on the second conductive semiconductorlayer 140. The reflective electrode layer may be formed of Al, Ag, Pd,Rh, or Pt and may improve reflective efficiency when a chip is mountedthrough a flip method. If the reflective electrode layer is formed onthe second conductive semiconductor layer 140, the second electrode 170may not be additionally formed.

The second electrode 170 and the second electrode pad 175 may be formedof at least one layer using a mixed material comprising at least one ofAg, Ag alloy, Ni, Al, Al alloy, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf,but are not limited thereto.

The second electrode 170 may have at least one of a line-shaped pattern,a curve-shaped pattern, a line and curve mixed pattern, a branch-shapedpattern branching one pattern into the plural number of patterns, apolygonal pattern, a striped pattern, a lattice pattern, a dot pattern,a diapered pattern, a parallelogram pattern, a mesh pattern, a streakpattern, a cross pattern, a radial pattern, and a combinational patternthereof, but is not limited thereto.

If the second electrode 170 is formed of a lattice pattern of apolygonal form such as a quadrangle form, a pentagonal form, and ahexagonal form, the second electrode 170 may be disposed along theoutline of a chip and a peripheral region of the chip center.

The second electrode pad 175 may be electrically connected to apredetermined position of the second electrode 170. The second electrodepad 175 may be formed in single or plurality, and the plurality ofsecond electrode pads 175 may be disposed separated from each other. Thesecond electrode pad 175 is disposed on a region where the secondelectrode 170 intersects, or formed at a pattern diverging from thesecond electrode 170. Additionally, the second electrode pad 175 may bedisposed on the center region, a center peripheral region, and the edgeregion, and the center region of each side, but is not limited thereto.

Here, the second electrode pad 175 may be a portion of the secondelectrode 170 or may be additionally formed in the second electrode 170.

The second electrode part 170 and 175 diffuses current and supplies itthrough the transparent electrode layer 145 and the second conductivesemiconductor layer 140. The second electrode part 170 and 175 preventscurrent from being concentrated on one area and improves tolerance forESD.

The insulation layer 150 is formed on the transparent electrode layer145 and the second electrode 170. The insulation layer 150 may berealized with an insulating material or a dielectric substance. Forexample, an insulation layer 150 may be formed of a silicon oxide (e.g.,SiO₂, etc.), a silicon nitride (e.g., Si_(x)N, etc.), a metal oxide(e.g., a Ti oxide), but is not limited thereto.

A second pad hole 151 is formed in the insulation layer 150 and thesecond electrode pad 175 is exposed through the second pad hole 151.

First electrode part 160 and 165 is formed on the insulation layer 150,and comprises a first electrode 160 and a first electrode pad 165. Thefirst electrode 160 and the first electrode pad 165 may be formed of atleast one or a plurality of mixed material selected from Ti, Al, In, Ta,Pd, Co, Ni, Si, Ge, Ag, and Au, and may be formed with a single layer ormulti layer structure. The first electrode pad 165 may be used as aportion of the first electrode 160 or may be additionally formed.

The first electrode 160 may have at least one of a line-shaped pattern,a curve-shaped pattern, a line and curve mixed pattern, a branch-shapedpattern branching one pattern into the plural number of patterns, apolygonal pattern, a striped pattern, a lattice pattern, a dot pattern,a diapered pattern, a parallelogram pattern, a mesh pattern, a streakpattern, a cross pattern, a radial pattern, and a combinational patternthereof, but is not limited thereto.

The first electrode 160 is formed of a pattern of a polygonal form suchas a quadrangle form, a pentagonal form, and a hexagonal form. In a caseof the pattern of the polygonal form, it may be formed along the chipoutline region and a chip peripheral region.

The first electrode 160 is formed on the insulation layer 150, and thesecond electrode 170 is formed under the insulation layer 150. The firstelectrode 160 has a via electrode structure, and may be disposed on theinsulation layer 150, crossing over the second electrode 170.

Additionally, the first electrode 160 may be arranged on the insulationlayer 150 to overlap a partial pattern of the second electrode 170. Thefirst electrode 160 and the second electrode 170 overlap spatially. Theoverlap interval or the size of the overlap area may vary according tothe pattern formation of the first electrode 160 and the secondelectrode 170.

If the first electrode 160 overlaps a partial pattern of the secondelectrode 170 spatially, the reduction of a light emitting area can beprevented and thus external light emitting efficiency can be improved.

The first electrode pad 165 and the second electrode pad 175 may bedisposed on a region for efficient power supply, and the region may bein single or plurality.

Referring to FIGS. 2 and 3, at least one of the first electrode 160 andthe first electrode pad 165 may comprise at least one via electrode 163.

If the first electrode 160 has a polygonal pattern, it comprises adiverge electrode 161 diverging toward an inner side direction, adiverge node 162 connected to the diverge electrode 161, and a viaelectrode 163 of a via form connected to the diverge node 162. The viaelectrode 163 is formed through the electrode hole 127 and the firstelectrode hole 152 is formed in the via hole 125.

The diverge electrode 161 may diverge into at least one branch form inthe pattern of the first electrode 160, and in a case of a multi-branch(e.g., a fork form), the branches are spaced a predetermined intervalfrom each other.

If the first electrode 160 is formed with a pattern of a polygonal form,the diverge electrode 161 may diverge toward the pattern inner directionor/and outer direction of the polygonal form, and a diverge node 162 andthe first electrode pad 165 may be electrically connected to the endportion of the diverge electrode 161.

At least one of a portion of the first electrode 160 and the firstelectrode pad 165 may become the diverge node 162. The diverge node 162may be formed in single or plurality in the first electrode part 160 and165.

The via electrode 163 is formed under the diverge node 162, and the viaelectrode 163 may be electrically connected to the first conductivesemiconductor layer 120, on the insulation layer 150, with a via form.Additionally, the via electrode 163 comprises a via hole 125, a secondelectrode hole 127, and an insulation part 155.

The via hole 125 perpendicularly penetrates the insulation layer 150,the transparent electrode layer 145, the second conductive semiconductorlayer 140, the active layer 130, and a portion of the first conductivesemiconductor layer 120.

The via hole 125 may be formed with a circular pillar form or apolygonal pillar form, but is not limited thereto. The via hole 125 maybe formed with a predetermined length and a predetermined width, andalso may be formed with the same pipe diameter or respectively differentpipe diameters.

The insulation portion 155 is filled in the surrounding of the via hole125 to insulate the via electrode 163. Accordingly, the via electrode163 is electrically insulated from other layers 145, 140, and 130. Thefirst electrode 160 ohmic-contacts the first conductive semiconductorlayer 120 through the via electrode 163.

The electrode hole 127 is formed in the inside of the insulation part155 of the via hole 125, and is formed along the insulation part 155,from the insulation layer 150 to the first conductive semiconductorlayer 120. The insulation part 155 electrically insulates the perimetersurface of the via electrode 163.

The bottom of the via electrode 163 contacts the top of the firstconductive semiconductor layer 120 or the inner side of the firstconductive semiconductor layer, or may penetrate the first conductivesemiconductor layer 120. The via electrode 163 ohmic-contacts the firstconductive semiconductor layer 120 and is disconnected from the otherlayers.

Once power is supplied through the first electrode pad 165, the suppliedpower is directly applied to the first conductive semiconductor layer120, and is diffused through the first electrode 160 connected to thefirst electrode pad 165. Then, the power is delivered to the firstconductive semiconductor layer 120 through the via electrode 163.Accordingly, the first electrode 150 can supply current to an entireregion of the first conductive semiconductor layer 110.

FIG. 4 is a plan view of FIG. 1 and illustrates an example of currentdistribution in an electrode part.

Referring to FIGS. 1 to 4, once power is supplied through the secondelectrode pad 175 and the first electrode pad 165, the current suppliedto the second electrode pad 175 is delivered to the transparentelectrode layer 145 and the second conductive semiconductor layer 140through the second electrode pad 175. The delivered current is uniformlysupplied to an entire region of the transparent electrode part 145through the second electrode 170 connected to second electrode pad 175.

The current supplied to the first electrode pad 165 is directly appliedto the first conductive semiconductor layer 120 through the viaelectrode 163, or diverges along the first electrode 160 through thediverge electrode 161. Then, the current is supplied to the firstconductive semiconductor layer 120 through the diverge node 162 and thevia electrode 163.

The current supplied to the first conductive semiconductor layer 120 isdiffused or distributed to an entire region through the plurality of viaelectrodes 163.

Accordingly, since the current is supplied to an entire region of thefirst conductive semiconductor layer 120 and the second conductivesemiconductor layer 140, the active layer 130 can improve an inner lightemitting efficiency and also improves tolerance for ESD.

FIGS. 5 to 16 are views illustrating a process of fabricating asemiconductor light emitting device according to a first embodiment.

Referring to FIG. 5, a light emitting structure 115 is formed on asubstrate 110. The substrate 110 may be formed of one selected from thegroup comprising Al₂0₃, GaN, SiC, ZnO, Si, GaP, InP, and GaAs. A convexand concave pattern may be formed on the substrate 110, and has a lensform.

Another semiconductor layer, for example, a buffer layer (not shown)or/and an undoped semiconductor layer (not shown), may be formed betweenthe substrate 110 and the light emitting structure 115. The buffer layerand the undoped semiconductor layer are disposed to reduce a latticeconstant difference between the substrate 110 and a nitridesemiconductor or prevent defectiveness.

The light emitting structure 115 comprises a first conductivesemiconductor layer 120, an active layer 130, and a second conductivesemiconductor layer 140.

The first conductive semiconductor layer 120 is formed on the substrate110. The first conductive semiconductor layer 120 may be realized with asemiconductor having an empirical formula of In_(x)Al_(y)Ga_(1-x-y)N(0≦x≦1, 0≦y≦1, 0≦x+y≦1) and is doped with a first conductive dopant. Thefirst conductive semiconductor layer 120 is a compound semiconductor ofa group III element and a group V element and may be formed of GaN, InN,AlN, InGaN, AlGaN, InAlGaN, or AlInN. When the first conductivesemiconductor layer 120 is an N-type semiconductor layer, the firstconductive dopant is an N-type dopant and the N-type dopant comprisesSi, Ge, or Sn.

The active layer 130 is formed on the first conductive semiconductorlayer 120. The active layer 130 may have a single quantum well structureor a multi quantum well structure. The active layer 130 has a period ofa well layer and a barrier layer through a compound semiconductormaterial of a group III element and a group V element. For example theperiod may comprise a period of an InGaN well layer/a GaN barrier layeror a period of an AlGaN well layer/a GaN barrier layer. The active layer130 may comprise a material for emitting colored light such as bluewavelength light, red wavelength light, and a green wavelength light.

A conductive clad layer (not shown) may be formed on or/and under theactive layer 130, and the conductive clad layer may be realized with anAlGaN layer.

A second conductive semiconductor layer 140 is formed on the activelayer 130. The second conductive semiconductor layer 140 may be realizedwith a semiconductor having an empirical formula ofIn_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1) and is doped with asecond conductive dopant. The second conductive semiconductor layer 140may be formed of a compound semiconductor of a group III element and agroup V element such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.When the second conductive semiconductor layer 140 is a P-typesemiconductor layer, the second conductive dopant is a P-type dopant,and the P-type dopant comprises Mg, Zn, Ca, Sr, or Ba.

Additionally, a third conductive semiconductor layer (not shown) isformed on the second conductive semiconductor layer 140. The thirdconductive semiconductor layer may be formed of an N-type semiconductorlayer if the second conductive semiconductor layer 140 is formed of aP-type semiconductor layer, and the third conductive semiconductor layermay be formed of a P-type semiconductor layer if the second conductivesemiconductor layer is formed of an N-type semiconductor layer.

The light emitting structure 115 may be formed of a P-N junction, an N-Pjunction, a P-N-P junction, or an N-P-N junction within the technicalscope of embodiments. Each layer may be formed of a single layer or amulti layer, and another semiconductor layer may be added on or undereach layer. Each layer is not limited to a stacked layer structure ofthe components.

When the second conductive semiconductor layer 140 is formed, mesaetching is performed on a channel region, that is, the chip boundaryregion, to expose an outer region of the first conductive semiconductorlayer 120, and this process may not be performed.

Referring to FIGS. 5 to 7, during the mesa etching, at least one viahole 125 is formed. The via hole 125 penetrates from the secondconductive semiconductor layer 140 to a portion of the first conductivesemiconductor layer 120, or may penetrates the first conductivesemiconductor layer 120.

Here, the forming of the via hole 125 may be performed after the formingof the second conductive semiconductor layer 140, or after the formingof the transparent electrode layer 145. The via hole 125 may have acircular pillar form or a polygonal pillar form, but is not limitedthereto.

Referring to FIGS. 6 and 7, the transparent electrode layer 145 isformed on the second conductive semiconductor layer 140. At this point,since a mask pattern is formed around the via hole 125, foreignmaterials are prevented from flowing into the via hole 125.

FIG. 8 is a plan view of the transparent electrode layer 145. Referringto FIGS. 7 and 8, the diameter D2 of the via hole 125 in the transparentelectrode layer 145 may be formed greater than that of the via holethereunder.

The transparent layer 145 may be formed of at least one of materials forlight transmittivity and ohmic-contact such as ITO, ZnO, RuOx, TiOx,IrOx, and NiAu. The transparent electrode layer 145 may not be formed,or a reflective electrode layer other than the transparent electrodelayer 145 can be formed.

Referring to FIGS. 9 and 10, once the transparent electrode layer 145 isformed, a second electrode part 170 and 175 is formed on the transparentelectrode layer 145. The second electrode part 170 and 175 comprises asecond electrode 170 and a second electrode pad 175. The secondelectrode part 170 may be formed of at least one layer using one of Ag,Ag alloy, Ni, Al, Al alloy, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, and amixed material thereof, but is not limited thereto.

The second electrode pad 175 may be formed on the transparent electrodelayer 145 or/and the second conductive semiconductor layer 140. Thesecond electrode pad 175 may be electrically connected to the secondconductive semiconductor layer 140 by forming hole in the transparentelectrode layer 145.

Additionally, the second electrode part 170 and 175 may be formed on thesecond conductive semiconductor layer 140 if the transparent electrodelayer 145 is not formed. Additionally, if a reflective electrode layeris formed on the second conductive semiconductor layer 140, the secondelectrode may not be formed.

The second electrode 170 may have at least one of a line-shaped pattern,a curve-shaped pattern, a line and curve mixed pattern, a branch-shapedpattern branching one pattern into the plural number of patterns, apolygonal pattern, a striped pattern, a lattice pattern, a dot pattern,a diapered pattern, a parallelogram pattern, a mesh pattern, a streakpattern, a cross pattern, a radial pattern, and a combinational patternthereof, but is not limited thereto.

The second electrode 170 may be formed with a lattice pattern of apolygonal form such as a quadrangle form, a pentagonal form, and ahexagonal form. In a case of the pattern of the polygonal form, thesecond electrode 170 may be disposed along the chip circumference, thechip center region, or a center peripheral region.

The second electrode pad 175 may be electrically connected to apredetermined position of the second electrode 170. The second electrodepad 175 may be formed in single or plurality, and the plurality ofsecond electrode pads 175 may be disposed separated from each other. Thesecond electrode pad 175 is disposed on a region where the secondelectrode 170 intersects, or formed at a pattern diverging from thesecond electrode 170. Additionally, the second electrode pad 175 may bedisposed on the center region, a center peripheral region, and the edgeregion, and the center region of each side, but is not limited thereto.

Here, the second electrode pad 175 may be a portion of the secondelectrode 170 or may be additionally formed in the second electrode 170.

The second electrode part 170 and 175 diffuses current and supplies itthrough the transparent electrode layer 145 and the second conductivesemiconductor layer 140. The second electrode part 170 and 175 preventscurrent from being concentrated on one area and improves tolerance forESD.

Here, during the forming of the second electrode part 170 and 175, anelectrode material is prevented from flowing in the via hole 125 bymasking it with a mask pattern or forming a dam structure.

Referring to FIGS. 11 and 13, once the second electrode parts 170 and175 are formed, an insulation layer 150 is formed on the transparentelectrode layer 145, the second electrode parts 170 and 175, and the viahole 125. The insulation layer 150 may be formed of a silicon oxide(e.g., SiO₂, etc.), a silicon nitride (e.g., Si_(x)N, etc.), a metaloxide (e.g., a Ti oxide), but is not limited thereto.

A second pad hole 151 is formed in the insulation layer 150, and thesecond electrode pad 175 is exposed through the second pad hole 151.

as illustrated in FIG. 12, the insulation part 155, i.e., a portion ofthe insulation layer 150, is formed in the via hole 125, and anelectrode hole 127 is formed in the insulation part 155. the depthexposing the first conductive semiconductor layer 120 in the insulationlayer is formed.

An electrode hole 152 may be formed through wet etching or plasmaetching. The diameter of the electrode hole 152 may be smaller than that(D2 of FIG. 7) of the via hole 125 of FIG. 7.

Additionally, the forming of the insulation layer 150 may be performedat least one time or a partial etching process can be repeatedlyperformed in order to form the via hole 125 and the electrode hole 125,but is not limited thereto.

The electrode hole 152 may be formed with the depth identical to ordeeper than that of the via hole.

Insulation layer 150 and 155 are formed on the electrode hole 152 andthe via hole 125 of FIG. 7. Here, the insulation layer 150 does not flowinto the second pad hole 151 because of a mask pattern.

Referring to FIGS. 12 and 13, first electrode part 160 and 165 is formedon the insulation layer 150. The first electrode part 160 and 165comprises a first electrode 160 and a first electrode pad 165.

The first electrode 160 and the first electrode pad 165 may be formed ofat least one or a plurality of mixed material selected from Ti, Al, In,Ta, Pd, Co, Ni, Si, Ge, Ag, and Au, and may be formed with a singlelayer or multi layer structure. The first electrode pad 165 may be usedas a portion of the first electrode 160 or may be additionally formed.

The first electrode 160 is formed of a pattern of a polygonal form suchas a quadrangle form, a pentagonal form, and a hexagonal form. The firstelectrode 160 may have at least one of a line-shaped pattern, acurve-shaped pattern, a line and curve mixed pattern, a branch-shapedpattern branching one pattern into the plural number of patterns, apolygonal pattern, a striped pattern, a lattice pattern, a dot pattern,a diapered pattern, a parallelogram pattern, a mesh pattern, a streakpattern, a cross pattern, a radial pattern, and a combinational patternthereof, but is not limited thereto.

The first electrode 160 comprises a diverge electrode 161 divergingtoward the inner side direction and a via electrode 163 connected to thediverge electrode 161. The diverge electrode 161 may diverge into atleast one branch form in the pattern of the first electrode 160, and ina case of a multi-branch (e.g., a fork form), the branches are spaced apredetermined interval from each other.

If the first electrode 160 is formed with a pattern of a polygonal form,the diverge electrode 161 may diverge toward the pattern inner directionor/and outer direction of the polygonal form, and a diverge node 162 andthe first electrode pad 165 may be electrically connected to the endportion of the diverge electrode 161.

The electrode hole 127 is disposed under diverge node 162 and/or thefirst electrode pad 165, and the electrode hole 152 is filled with afirst electrode material to form the via electrode 163.

The via electrode 163 may ohmic-contact the first conductivesemiconductor layer 120 through the electrode hole 127.

Since a via electrode 163 is formed under the diverge node 162 and thefirst electrode pad 165, it may be electrically connected to the firstconductive semiconductor layer 120 in a via form.

A partial pattern of the first electrode 160 may overlap a partialpattern of the second electrode 170. The first electrode 160 and thesecond electrode 170 are disposed at both sides of the insulation layer150, and partial patterns of the first and second electrodes 160 and 170may overlap spatially at both sides of the insulation layer 150.

Additionally, the patterns of the first electrode 160 and the secondelectrode 170 are disposed crossing over each other, but are not limitedto the overlapping structure.

A first electrode part 160 and 165 and the second electrode pad 175 areexposed on the insulation layer 150.

Additionally, the first electrode pad 165 and the second electrode pad175 are spaced apart from each other, and may be disposed on the centerregion, the center peripheral region, the edge region, and the center ofeach side of a chip, but are not limited thereto.

Since partial patterns of the first and second electrodes 160 and 170overlap spatially, light emitting area reduction of the active layer 130can be prevented and thus external light emitting efficiency can beimproved.

FIGS. 17 to 20 are views illustrating a process of fabricating asemiconductor light emitting device according to a second embodiment.When describing the second embodiment, overlapping description relatedto the first embodiment will be omitted for conciseness.

Referring to FIG. 17, a first conductive semiconductor layer 120, anactive layer 130, and a second conductive semiconductor layer 140 aresequentially formed on a substrate 110. Another semiconductor layer maybe formed on/under each of the semiconductor layer, but is not limitedthereto.

Once the second conductive semiconductor layer 140 is formed, mesaetching is performed on the channel region (i.e., a chip boundaryregion) to expose the outer region of the first semiconductor layer 120.The process may not be performed.

During the mesa etching, at least one via hole 125 is formed. The viahole 125 penetrates from the second conductive semiconductor layer 140to a portion of the first conductive semiconductor layer 120, or passesthrough the first conductive semiconductor layer 120.

Here, the forming of the via hole 125 may be performed after the formingof the second conductive semiconductor layer 140 or the forming of thetransparent electrode layer. The via hole 125 may have a circular pillarform or a polygonal pillar form, but is not limited thereto.

A transparent electrode layer 145 is formed on the second conductivesemiconductor layer 140. A second electrode part 170 and 175 and a viaelectrode 163A are formed on the transparent electrode layer 145.

At this point, the second electrode part 170 and 175 comprises a secondelectrode 170 of a predetermined pattern and at least one secondelectrode pad 175. For example, the second electrode part 170 and 175may be formed of at least one layer using a mixed material comprising atleast one of Ag, Ag alloy, Ni, Al, Al alloy, Rh, Pd, Ir, Ru, Mg, Zn, Pt,Au, and Hf, but are not limited thereto. The second electrode part 170and 175 refers to the first embodiment.

The via electrode 163A is formed with a predetermined thickness in thevia hole 125. One end of the via electrode 163A contacts on the firstconductive semiconductor layer 120, and does not contact the otherlayers 130, 140, and 145.

Here, the second electrode part 170 and 175 and the via electrode 163Aare formed through the same process. In this case, the second electrodepart 170 and 175 and the via electrode 163A are formed of the samematerial.

Additionally, the second electrode part 170 and 175 are formed throughseparate processes. For example, after the forming of the secondelectrode part 170 and 175, the via electrode 163A can be formed. Or,after the forming of the via electrode 163A, the second electrode part170 and 175 can be formed. This process order may vary.

The second electrode part 170 and 175 diffuses current through thetransparent electrode layer 145 and the second conductive semiconductorlayer 140 and then supplies it. The second electrode part 170 and 175prevents current to be concentrated on one place such that tolerance forESD can be improved.

Referring to FIGS. 18 and 19, once the second electrode part 170 and 175and the via electrode 163A are formed, an insulation layer 150 isformed. The insulation layer 150 is formed on the transparent electrodelayer 145 and the second electrode part 170 and 175. A portion of theinsulation layer 150 is formed around the via hole 125 to insulate thevia electrode 163A.

The insulation layer 150 may be formed of a silicon oxide (e.g., SiO₂,etc.), a silicon nitride (e.g., Si_(x)N, etc.), a metal oxide (e.g., aTi oxide), but is not limited thereto.

A second pad hole 151 is formed in the insulation layer 150, and thesecond electrode pad 175 is opened through the second pad hole 151.

At least one electrode hole 127A is formed in the insulation part 155.The electrode hole 127A has a depth by which the via electrode 163A isexposed.

The electrode hole 127A may be formed through wet etching or plasmaetching. The diameter of the electrode hole 127A may be identical to orless than that of the via electrode 163A, but is not limited thereto.

Referring to FIGS. 19 and 20, a first electrode part 160 and 165 isformed on the insulation layer 150. The first electrode part 160 and 165comprises a first electrode 160 of a predetermined pattern and at leastone first electrode pad 165.

The first electrode 160 and the first electrode pad 165 may be formed ofat least one or a plurality of mixed material selected from Ti, Al, In,Ta, Pd, Co, Ni, Si, Ge, Ag, and Au, and may be formed with a singlelayer or multi layer structure. The first electrode pad 165 may be usedas a portion of the first electrode 160 or may be additionally formed.The first electrode part 160 and 165 refers to the first embodiment.

A diverge node 162 of the first electrode 160 is electrically connectedto the via electrode 163A, with the form of the via electrode 163B. Thatis, the via electrode 163B is connected to the via electrode 163 whenthe electrode hole 127A is filled with a first electrode material.

Since the via electrodes 163A and 163B are formed under the diverge node162 and the first electrode pad 165, it is electrically connected to thefirst conductive semiconductor layer 120, in a via form.

A partial pattern of the first electrode 160 may overlap a partialpattern of the second electrode 170. The first electrode 160 and thesecond electrode 170 are disposed at both sides of the insulation layer150, and partial patterns of the first electrode 160 and the secondelectrode 170 spatially overlap at the both sides of the insulationlayer 150.

In the description of embodiments, it will be understood that when eachlayer (or film), area, pattern, or structure is referred to as being“on/under” another substrate, layer (or film), area, pad, or pattern, itcan be “directly” on the another substrate, layer (or film), area, pad,or pattern, or intervening layers may also be “indirectly” present.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

INDUSTRIAL APPLICABILITY

Embodiments provide a semiconductor light emitting device.

Embodiments provide the degree of pattern freedom for a semiconductorlight emitting device.

1. A semiconductor light emitting device, comprising: a first conductivesemiconductor layer; an active layer on the first conductivesemiconductor layer; a second conductive semiconductor layer on theactive layer; a second electrode part on the second conductivesemiconductor layer; an insulation layer on the second electrode part;and a first electrode part on the insulation layer, a portion of thefirst electrode part being electrically connected to the firstconductive semiconductor layer, wherein the insulation layer is disposedbetween the first electrode part and the second electrode part, whereinthe insulation layer includes a first hole and a via hole spaced apartfrom the first hole, and wherein a portion of the second electrode partis disposed in the first hole of the insulation layer.
 2. Thesemiconductor light emitting device according to claim 1, wherein thefirst electrode part comprises: a first electrode comprising at leastone form of a pattern; at least one first electrode pad connected thefirst electrode; and a connection electrode in at least one of the firstelectrode and the first electrode pad.
 3. The semiconductor lightemitting device according to claim 2, wherein the connection electrodeis disposed in the via hole perpendicularly penetrating the insulationlayer, the second conductive semiconductor layer, the active layer, anda portion of the first conductive semiconductor layer; and theinsulation layer is further disposed on a circumference of theconnection electrode in the via hole.
 4. The semiconductor lightemitting device according to claim 2, wherein the first electrodecomprises at least one of a line-shaped pattern, a curve-shaped pattern,a line and curve mixed pattern, a branch-shaped pattern branching onepattern into the plural number of patterns, a polygonal pattern, astriped pattern, a lattice pattern, a dot pattern, a diapered pattern, aparallelogram pattern, a mesh pattern, a streak pattern, a crosspattern, a radial pattern, and a combinational pattern thereof.
 5. Thesemiconductor light emitting device according to claim 1, comprising: atransparent electrode layer between the second conductive semiconductorlayer and the second electrode part, wherein the second electrode partis connected to at least one of the second conductive semiconductorlayer and the transparent electrode layer.
 6. The semiconductor lightemitting device according to claim 1, wherein the second electrode partcomprises: a second electrode comprising at least one form of a pattern;and a second electrode pad connected to the second electrode anddisposed in the first hole of the insulation layer.
 7. The semiconductorlight emitting device according to claim 6, wherein the second electrodecomprises at least one of a line-shaped pattern, a curve-shaped pattern,a line and curve mixed pattern, a branch-shaped pattern branching onepattern into the plural number of patterns, a polygonal pattern, astriped pattern, a lattice pattern, a dot pattern, a diapered pattern, aparallelogram pattern, a mesh pattern, a streak pattern, a crosspattern, a radial pattern, and a combinational pattern thereof.
 8. Thesemiconductor light emitting device according to claim 1, wherein afirst portion of the first electrode part on the insulation layeroverlaps spatially a first portion of the second electrode part underthe insulation layer and the second electrode part is disposed aroundthe portion of the first electrode part.
 9. A semiconductor lightemitting device, comprising: a first conductive semiconductor layer; anactive layer on the first conductive semiconductor layer; a secondconductive semiconductor layer on the active layer; a second electrodepart on the second conductive semiconductor layer; an insulation layeron the second electrode part; a transparent electrode layer disposedbetween the second electrode part and the second conductivesemiconductor layer; and a first electrode part on the insulation layer,a portion of the first electrode part being electrically connected tothe first conductive semiconductor layer through a via hole, wherein thetransparent electrode layer includes a hole and the portion of the firstelectrode part is disposed in the hole.
 10. The semiconductor lightemitting device according to claim 9, wherein the first electrode partcomprises: a first electrode comprising at least one form of a pattern;at least one first electrode pad connected to the first electrode; andat least one connection electrode in at least one of the first electrodeand the first electrode pad, the connection electrode being electricallyconnected to the first conductive semiconductor layer.
 11. Thesemiconductor light emitting device according to claim 9, wherein theinsulation layer comprises a second pad hole exposing the secondelectrode pad which is disposed in the second pad hole.
 12. Thesemiconductor light emitting device according to claim 9, wherein: atleast one of the first electrode part and the second electrode partcomprises at least one of a line-shaped pattern, a curve-shaped pattern,a line and curve mixed pattern, a branch-shaped pattern branching onepattern into the plural number of patterns, a polygonal pattern, astriped pattern, a lattice pattern, a dot pattern, a diapered pattern, aparallelogram pattern, a mesh pattern, a streak pattern, a crosspattern, a radial pattern, and a combinational pattern thereof; and thefirst electrode part and the second electrode part are disposed crossingover each other at both sides of the insulation layer or partialpatterns thereof overlap each other.
 13. The semiconductor lightemitting device according to claim 9, wherein the transparent electrodelayer includes a transparent electrode layer or a reflective electrodelayer.
 14. A semiconductor light emitting device comprising: a lightemitting structure including a first conductive semiconductor layer, asecond conductive semiconductor layer, and an active layer between thefirst conductive semiconductor layer and the second conductivesemiconductor layer; an insulation layer on the light emittingstructure, the insulation layer including a plurality of holes; a secondelectrode between the insulation layer and the light emitting structure;a second pad connected to the second electrode, the second pad disposedin at least one of the holes of the insulation layer; a first electrodeon the insulation layer; and a connection electrode connected betweenthe first electrode and the first conductive semiconductor layer. 15.The semiconductor light emitting device according to claim 14, whereinthe connection electrode includes a first portion in contact with thefirst conductive semiconductor layer and a second portion in contactwith the first electrode, wherein the second portion of the connectionelectrode has a width smaller than that of the first portion of theconnection electrode.
 16. The semiconductor light emitting deviceaccording to claim 14, wherein a portion of the insulation layer isdisposed between an inner portion of the light emitting structure andthe connection electrode.
 17. The semiconductor light emitting deviceaccording to claim 14, wherein the connection electrode is disposed on acenter area of patterns of the second electrode.
 18. The semiconductorlight emitting device according to claim 14, wherein a first portion ofthe first electrode overlaps spatially a first portion of the secondelectrode.
 19. The semiconductor light emitting device according toclaim 18, wherein the first portion of the first electrode and the firstportion of the second electrode include a loop shape or/and a lineshape.
 20. The semiconductor light emitting device according to claim14, comprising a substrate under the light emitting structure, and atransparent electrode layer between the insulation layer and the lightemitting structure.